Life and health

Hyperlacrimation

Hyperlacrimation (ICD-11 9A10.3) is overflow of tears from excessive lacrimal gland secretion, caused by drugs, emotion, or trigeminal reflex irritation; distinct from epiphora, a drainage failure.

Hyperlexia: precocious, self-taught word reading far exceeding comprehension, usually with autism (about 84% of cases); coined by Silberberg and Silberberg in 1967; not a standalone DSM-5 diagnosis; three described types.

Hyperlipidemia

Hyperlipidemia (hypercholesterolemia, lipid disorder) is abnormally high blood lipids or lipoproteins. High LDL and triglycerides drive atherosclerosis; detected by lipid profile, treated with statins, ezetimibe, PCSK9 inhibitors.

Hypermagnesemia

Hypermagnesaemia (hypermagnesemia; ICD-10-CM E83.41) is an elevated serum magnesium level, defined above 2.6 mg/dL (1.05 mmol/L). Rare, usually caused by kidney failure with magnesium intake; causes reflex loss, hypotension, respiratory depression; treated with calcium gluconate, furosemide, or dialysis.

Hypermanganesemia with dystonia

Hypermanganesemia with dystonia is a rare autosomal recessive disorder in which mutations in SLC30A10 or SLC39A14 cause manganese to accumulate in the blood and brain.

Hypermetabolism

Hypermetabolism is an abnormally fast metabolism causing weight loss and fatigue, seen after severe burns (REE 40-80% above normal, lasting up to two years), sepsis, eating disorder recovery, hyperthyroidism, and cancer.

Hypermetamorphosis

Hypermetamorphosis: a form of complete insect metamorphosis (holometaboly) in which larval instars differ markedly in form, seen in Mantispidae, Meloidae blister beetles, Rhipiphoridae, and Strepsiptera, with type I and type II patterns.

Hypermethioninemia

Hypermethioninemia, also called methioninemia, is an excess of the amino acid methionine in the blood, arising from inherited enzyme defects, liver disease, or unusually high dietary intake.

Hypermethioninemia due to glycine N-methyltransferase deficiency

Hypermethioninemia due to glycine N-methyltransferase deficiency (GNMT deficiency, OMIM 606664) is a rare autosomal recessive disorder causing permanent marked hypermethioninemia with high AdoMet, normal AdoHcy, and mild liver enzyme elevations.

Hypermetropia

Hypermetropia, also called hyperopia or farsightedness, is a refractive error in which light focuses behind the retina with accommodation relaxed, blurring near vision; caused by short axial length or flat cornea, corrected with plus lenses.

Hypermobile Ehlers-Danlos syndrome

Hypermobile Ehlers-Danlos syndrome (hEDS), formerly EDS type III, is the most common Ehlers-Danlos type: a clinically diagnosed connective tissue disorder with joint hypermobility, no known gene, prevalence about 1:3,100, and updated criteria due December 2026.

Hypermobility (joints)

Joint hypermobility, also called being double-jointed, means joints with unusually large range of movement; assessed by the Beighton Score, it ranges from an asymptomatic trait to hypermobility spectrum disorders and hypermobile Ehlers-Danlos syndrome.

Hypernatremia

Hypernatremia is a serum sodium above 145 mmol/L from a water deficit relative to sodium, causing thirst and neurologic symptoms; treatment is controlled water replacement, with recent evidence favoring faster correction in admission-related and severe cases.

Hyperolius

Hyperolius (reed frogs, African reed frogs), genus Rapp 1842 of family Hyperoliidae; most speciose sub-Saharan amphibian genus, ~146 species, includes H. viridiflavus superspecies with 50+ subspecies.

Hyperoodon

Hyperoodon, bottlenose whales, is a beaked-whale genus (Ziphiidae) with two antitropical species: H. ampullatus of the North Atlantic and H. planifrons of the Southern Ocean; deep-diving, whaling-depleted, COSEWIC-listed.

Hyperoplus lanceolatus

Hyperoplus lanceolatus (Le Sauvage, 1824), greater sandeel or great sandeel, largest Ammodytidae sand lance of the NE Atlantic to 40 cm; dark snout spot, two palate teeth, non-protrusible upper jaw; COI barcoding cannot separate it from Ammodytes tobianus.

Hyperosmia

Hyperosmia is a quantitatively increased sense of smell, defined as an exceptionally high psychophysical olfactory test score (above the 90th percentile); distinct from olfactory intolerance, and often contradicted by objective testing showing hyposmia.

Hyperosmolar hyperglycemic state

Hyperosmolar hyperglycemic state (HHS), formerly hyperglycemic hyperosmolar nonketotic coma: a life-threatening type 2 diabetes emergency with glucose over 600 mg/dL, osmolality over 320 mOsm/kg, dehydration without ketoacidosis, and 5–16% mortality.

Hyperostosis corticalis generalisata

Hyperostosis corticalis generalisata, or van Buchem disease, is a rare autosomal recessive craniotubular hyperostosis caused by a 52-kb SOST regulatory deletion, causing skull and mandible thickening, cranial nerve palsies, and hearing loss, mainly in the Dutch population.

Hyperostosis cranialis interna

Hyperostosis cranialis interna (HCI, OMIM 144755) is an extremely rare autosomal dominant bone dysplasia, first described in 1990, causing endosteal hyperostosis of the calvaria and skull base with cranial nerve I, II, V, VII, and VIII entrapment; mapped to chromosome 8p21, SLC39A14 implicated.

Hyperostosis of skull

Hyperostosis of skull (ICD-10 M85.2), chiefly hyperostosis frontalis interna, benign nodular thickening of the frontal bone's inner table, common in postmenopausal women, usually incidental.

Hyperparathyroidism

Hyperparathyroidism is a condition that occurs when the parathyroid glands excessively secrete parathyroid hormone. It can manifest in primary, secondary, or tertiary forms, impacting calcium levels.

Hyperparathyroidism-jaw tumor syndrome

Hyperparathyroidism-jaw tumor syndrome (HPT-JT, OMIM 145001) is a rare autosomal dominant CDC73/parafibromin disorder causing primary hyperparathyroidism, jaw ossifying fibromas, renal and uterine tumors, and parathyroid carcinoma risk.

Hyperphenylalaninemia due to tetrahydrobiopterin deficiency

Hyperphenylalaninemia due to tetrahydrobiopterin deficiency (BH4 deficiency, atypical/malignant PKU): rare autosomal recessive disorders of GCH1, PTS, QDPR, or PCBD1 causing elevated phenylalanine plus dopamine and serotonin deficiency, treated with BH4, L-dopa, and 5-hydroxytryptophan.

Hyperphosphatasia-intellectual disability syndrome

Hyperphosphatasia-intellectual disability syndrome (Mabry syndrome, HPMRS, ORPHA:247262) is a rare autosomal recessive GPI-anchor glycosylation disorder with intellectual disability, seizures, facial dysmorphism, and elevated alkaline phosphatase from PIGV, PIGO, PGAP2, PGAP3, PIGW, or PIGY variants.

Hyperpigmentation

Hyperpigmentation: excess melanin causing darker skin patches, mainly melasma and postinflammatory hyperpigmentation (PIH). Most common in Fitzpatrick phototypes III-VI; treated with sunscreen, hydroquinone, azelaic acid, retinoids, tranexamic acid, and procedures.